ABSTRACT
Linear electromagnetic machines (LEMs) develop electromagnetic forces based on Faraday’s and Ampere’s laws, and produce directly linear motion. Linear motion may be either progressive or oscillatory. Linear progressive motion even when experiencing back and forth, but nonperiodic, operation modes leads to LEMs whose topology differ from that of linear oscillatory machines. The progressive motion LEMs operate at variable voltage and frequency to vary speed at high efficiency for wide speed control ranges. LSMs provide linear motion high position speed control performance advantages, such as: high accuracy; high repeatability; and faster acceleration than rotary motors with rotary to linear transmission solutions. The linear oscillatory motion takes place in general at resonance—when mechanical eigenfrequency equals the electrical frequency—to secure high efficiency in the presence of a strong springlike force. The progressive motion LEMs are three-phase ac devices that operate in brushless configurations, while LOMs are typically single-phase ac devices.
